منابع مشابه
Neutron-capture Elements in the Metal-poor Globular Cluster M15
We report on observations of six giants in the globular cluster M15 (NGC 7078) using the Subaru Telescope to measure neutron-capture elemental abundances. Our abundance analyses based on high-quality blue spectra confirm the star-to-star scatter in the abundances of heavy neutron-capture elements (e.g., Eu), and no significant s-process contribution to them, as was found in previous studies. We...
متن کاملSolar Abundance of Elements from Neutron-capture Cross Sections
Introduction: Light elements, H and He, covering the solar surface are widely believed to be dominant inside the Sun [1]. Noting that gaseous envelopes may not reflect the Sun’s internal composition, Harkins [2] used analyses on 443 meteorites to conclude that Fe, O, Ni and Si are more abundant. B2FH [3] explained element synthesis in stars; decades later Fowler said laboratory and theoretical ...
متن کاملAn Infrared Survey of Neutron-capture Elements in Planetary Nebulae
We present results from an ongoing survey of the infrared emission lines [Kr III] 2.199 and [Se IV] 2.287 μm in Galactic planetary nebulae (PNe). Krypton and selenium may be produced by slow neutron-capture nucleosynthesis (the “s-process”) during the asymptotic giant branch (AGB) phase of PN progenitor stars, and brought to the surface by convective dredge-up before PN ejection. We detect emis...
متن کاملThe Abundances of Light Neutron-Capture Elements in Planetary Nebulae
We present preliminary results from a large-scale survey of the neutron(n)-capture elements Se and Kr in Galactic planetary nebulae (PNe). These elements may be produced in PN progenitors by s-process nucleosynthesis, and brought to the stellar envelope by third dredge-up (TDU). We have searched for [Kr III] 2.199 and [Se IV] 2.287 μm in 120 PNe, and detected one or both lines in 79 objects, fo...
متن کاملNeutron-capture elements in the s- and r-process-rich stars: Constraints on neutron-capture nucleosynthesis processes
The chemical abundances of the very metal-poor double-enhanced stars are excellent information for setting new constraints on models of neutron-capture processes at low metallicity. These stars are known as s+r stars, since they show enhancements of both s-process and r-process elements. The observed abundance ratios for the double-enhanced stars can be explained by those of stars that were pol...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2011
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361/201117584